1 roll puff pastry, thawed but cold
1/3 cup Béchamel sauce
75g Gruyère, grated
4 slices prosciutto
Preheat oven to 350F.
Prepare a baking tray with parchment paper.
Place pastry on baking tray.
Spread Béchamel on the rolled out pastry, leaving a 2cm border around the edge.
Layer prosciutto over Béchamel.
Sprinkle cheese over prosciutto.
Best the egg lightly and brush edges of the pastry with egg wash.
Bake for 25-30 minutes until cheese is golden and pastry puffed.